It's such a rarely used feature that I had to think about it for some time myself.

Well, it's a http proxy - it's only for the http connection. Http is the kind of connection that web browser makes, ie. it's not for email download (which can be pop3 or imap connection), but it's mostly for viewing images located online - usually those found in commercial newsletters.

Should you wish Pocomail to use a proxy email server (if that's how it's called), you shall change the server name directly in the account settings.
(Close example would be perhaps running a SpamBayes antispam, which is defacto a kind of email proxy. I have set localhost in account settings in Pocomail for incoming server, and the real incoming server for that account is then set in SpamBayes.)

recently, my employer changed the connection to the internet - now all internet traffic needs to go through a proxy server. Hence, in order to get access to internet with PocoMail, I need to configure the proxy connection.

I know the IP address of the proxy server, which I have entered under the "Network Settings" of the "Options" menu. However, as pocodog mentions, nothing changes - in my case I have no connection. Apparently, the connection is not diverted through the proxy server, because nothing changes when trying different IP addresses of different proxy servers also when connecting at home.

My question: how exactly does the proxy connection work? Has someone experience with it?

Thanks a lot for your help. I would really appreciate if I could use PocoMail through the proxy server (which now is the only way to access the internet for me).

Best,torros

PS Using the same proxy setting with other programs (e.g. STATA) works perfectly.